Katsura tree named ‘Biringer’

ABSTRACT

‘Biringer’ Katsura is a newly and distinct variety of Katsura tree ( Cercidiphyllum japonicum ) having characteristics that are of commercial value in the nursery trade. As compared to Common Katsura, ‘Biringer’ Katsura has darker green summer foliage; narrower, more upright branch angles; a tendency to hold the leaves later in the autumn; and greater winter hardiness.

Genus and species: Cercidiphyllum japonicum.

Variety denomination: ‘Biringer’.

BACKGROUND OF THE NEW VARIETY

The inventor discovered a single unusual tree in a row of Katsura treesat his commercial nursery in Mount Vernon, Wash. in July 2003. Thisunusual tree, believed to be a naturally occurring whole-plant mutationof Common Katsura, exhibited narrower, more upright branch angles anddarker green foliage than the surrounding Common Katsura trees (notpatented). This single tree was marked and observed during the remainderof 2003 and through 2004. In August 2004, 200 to 300 trees werepropagated by chip budding and by cuttings (mist propagation). Thepropagated trees were planted in 2005. All trees from this propagationappeared identical to the original tree. Since 2005, approximately 500trees have been propagated from the second-generation trees, and all areidentical, confirming the trueness to type of the new variety. The newKatsura tree has been given the name ‘Biringer’.

BRIEF SUMMARY OF THE INVENTION

The distinguishing characteristics of the ‘Biringer’ Katsura as comparedto Common Katsura are as follows:

-   -   1. Narrower, more upright growth habit.    -   2. Less vigor, by approximately 25-30%.    -   3. Darker green summer foliage.    -   4. Delayed senescence of leaves in the autumn, retaining foliage        approximately two weeks longer.    -   5. Greater winter hardiness.

DESCRIPTION OF THE DRAWINGS

FIG. 1 One-year shoots of Katsura, showing difference in senescencebetween ‘Biringer’ Katsura (top) and Common Katsura (bottom).

FIG. 2 Two-year old Katsura trees in nursery row. ‘Biringer’ Katsura isin the foreground on the left; Common Katsura is on the right.

FIG. 3 Three year old ‘Biringer’ Katsura trees in nursery row.

FIG. 4 Three year old Common Katsura trees in nursery row.

FIG. 5 Four year old ‘Biringer’ Katsura trees in nursery row.

DETAILED BOTANICAL DESCRIPTION

The Common Katsura tree, Cercidiphyllum japonicum, Siebold and Zucc. exJ.Hoffm. and H. Schult., is described in Hortus Third (MacMillan) asfollows: Upright-branching tree to 100 ft., trunk often branched abovethe base; leaves orbicular to ovate, to 4 in. long and cordate,crenate-serrate, glabrous, dark green above, glaucescent beneath,becoming yellow or scarlet in autumn; flowers before leaves; folliclesabout ¾ in. long.

The detailed description which follows documents the differences betweenthe Common Katsura tree and the claimed ‘Biringer’ Katsura tree. Thisdescription was prepared from observation and sampling of two year oldtrees at Mount Vernon, Skagit County, Wash. in October 2008. Certaincharacteristics of this variety, such as growth and color, may changewith changing environmental conditions, e.g., photoperiod, temperature,moisture, soil conditions, nutrient availability, or other factors.Color descriptions and other terminology are used in accordance withtheir ordinary dictionary descriptions unless the context clearlyindicates otherwise. Color designations (hue/value/chroma) are made withreference to the Munsell Book of Color, Kollmorgen Instruments Corp.,405 Little Britain Road, New Windsor, New York 12553.

-   Tree    -   -   Height.—Similar to that of Common Katsura, approximately 5            feet at end of first season in the nursery (FIG. 2).        -   Width.—First year 12 to 18 inches at the widest point,            approximately 6 inches narrower than Common Katsura.        -   Overall shape.—Upright branching tree. ‘Biringer’ has more            upright growth habit and reduced vigor compared to Common            Katsura, thus appearing more compact.-   Trunk    -   -   Texture.—Smooth.        -   Color.—Medium brown, (7.5 YR 5/4). No difference in trunk            bark texture or color from that of Common Katsura.-   Branches    -   -   Habit.—Upright branching, with side branches averaging 30            degrees from the vertical, compared to 45 degrees from the            vertical in Common Katsura.        -   Size.—About 60 to 90 cm long, and about 8 to 10 mm in            diameter at the base; Somewhat more slender and with about            30% less vigor than Common Katsura.        -   Color.—Olive brown, (2.5 Y 4/4), as compared to light brown            (10 R 4/4) in Common Katsura.        -   Lenticels.—Round to oblong, inconspicuous, light tan (7.5 YR            6/2), less than 1 mm in length and diameter.        -   Internode length.—5.5 cm, as compared to 6.0 cm in Common            Katsura.-   Leaves

Based on observation of 10 leaves on Oct. 11, 2008.

-   -   -   Size.—6.5 cm long and 6.5 cm wide, similar to Common            Katsura.        -   Form.—Orbicular to ovate, apex acuminate, base cordate;            similar to Common Katsura.        -   Texture.—Upper surface glabrous; lower surface glaucescent.        -   Color.—Dark green (2.5 G 3/4) above, lighter green (2.5 G            6/8) beneath. Upper surface of leaves on Common Katsura,            when sampled, were more yellowish (2.5 GY 4/4), showing            signs of senescence.        -   Marginal form.—Crenate and glabrous above, glaucescent            beneath, similar to that of Common Katsura.        -   Petiole.—2.7 cm in length, 2 mm in width, color reddish (2.5            R 3/10), as compared to a more purple color (2.5 R 3/4) in            Common Katsura.

-   Flowers    -   -   Blossoms.—No flowers have been observed. The inventor has            not observed flowers on Katsura trees. The literature            suggests that Katsura trees typically produce separate male            and female flowers in spring before foliation.        -   Seeds.—None observed.

-   Other Distinguishing Characteristics    -   -   Hardiness.—On Nov. 20, 2006, a low temperature of 12 degrees            Fahrenheit was reached in an area where Common and            ‘Biringer’ Katsura trees were growing. By the following            spring it was observed that more than 50% of the Common            Katsura trees died, while all of the sixty plants of            ‘Biringer’ cv. of the same age survived undamaged.        -   Disease/insect resistance and susceptibility.—No observable            difference in adaptability to various soil conditions,            disease and insect infestation, or fall coloring have been            observed between ‘Biringer’ Katsura and Common Katsura.

1. A new and distinct variety of Katsura tree named ‘Biringer’ as herein described and illustrated. 